The invention generally relates to paper making systems and processes, and relates in particular, to systems and processes for facilitating the removal of fluids from papermaking material during paper making processes.
In the paper making process the press section is equipped with conveying belts commonly referred to as felts. The felts act to carry the newly formed, very wet paper to the pressing rolls where a considerable amount of water is forced out of the paper and into the felts. As these felts are serpentine in nature, it is necessary to remove the captured water from the felts so that the process of water removal from the paper is repeated as the continuous supply of newly form paper is processed through the press section.
The existing methods for water extraction from the serpentine felt typically involve the use of a vacuum element in the belt run commonly referred to as the Uhle box, which is typically constructed from a pipe or enclosure that has a contact wear surface attached to it. This contact wear surface incorporates within the design a through path for the vacuum applied water extraction stream to drain into. The vacuum applied to the felt is considerable and causes the felt to be pulled tightly onto the contact wear surface and into the vacuum port open area.
The friction between the two components (felt and contact wear surface) must be minimized to prevent premature component wear and minimize the amount of energy consumed to drive the felts about their serpentine loop. The placement of a water application device commonly known as lube showers, sprays a coating of water onto the felt surface that is to be in contact with the Uhle box contact wear surface to prevent the buildup of friction generated heat and more importantly, to create a film of water for the felt to ride (hydro-plane) on as it travels over the vacuum through path(s) in the cover.
To apply the water the shower is typically located before the Uhle box and is equipped to evenly coat the felt surface through a multitude of nozzles populated on a common pipe, which is commonly referred to as the lube shower. A pressurized water supply insures application of the water to the felt surface. The use of the lube shower however, is not always effective in certain applications.
There remains a need therefore, for more efficient and effective systems for removing fluids from felts while minimizing wear on the felts.